Apparatus comprising a timing mechanism and an intermittent switching mechanism



Sept. 6, 1966 w. HOLZER 3,270,448

APPARATUS COMPRISING A TIMING MECHANISM AND AN INTERMITTENT SWITCHINGMECHANISM Filed March 29, 1965 Fig.2.

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ATTORNEYS ,sitates a re-selection of different time intervals.

United States Patent APPARATUS COMPRISING A TIMING MECHA- NISM AND ANINTERMITTENT SWITCHING MECHANISM Walter Holzer, Drosteweg 19, Meersburg(Bodensee),

Uberlingen (Bodensee), Baden, Germany Filed Mar. 29, 1965, Ser. No.443,590 4 Claims. (CI. 40-78) This is a continuation-in-part ofapplicants co-pending application Serial No. 167,715, filed January 22,1962, now Patent No. 3,210,487, issued October 5, 1965.

The invention relates to apparatus for automatically changingtransparencies in projectors.

It is an object of the invention to construct the apparatus in such away that it is robust, shockproof, substantially unaitected by voltagefluctuations, compact and cheap to manufacture.

An apparatus comprising a timing and intermittent switching mechanism isknown for progressively advancing a programme indexing disc, but whichcan be used for washing machines only and which is not suited forchanging pictures in projectors.

A known automatic control system for projectors and stereoscopescomprises a spring-actuated mechanism for a. wheel and locking device,wherein an electric magnet and armature are provided for the lockingaction. Neither a motor controlling the timing mechanism nor anothermotor for the step-by-step system are present. The timing must be veryexact, so it will operate in synchronism with the clockwork over thewhole range. This neces- It also calls for timing of a lighting currentcircuit, wherein the second-hand touches a contact.

Another known device for controlling electric circuits is in the form ofa punched card timing system, but in which there is no possibility ofintermittent operation of a switch to change pictures, wherein thetiming mechanism as well as the intermittent switching mechanism alwaysstart at the initial position.

For allocation of a series of still pictures to the text of a record,there has been proposed a device comprising a punched tape and contactspenetrating through the perforations for timing. With such a system thetime sequence is initially convertibly fixed. This is also true ofother, already known devices for projection of educational and/ orentertaining programmes, having a recording tape with metal foils forswitching.

There are also projectors for automatically showing a series oftransparencies. The projection times however cannot be adjusted but aredependent upon the uniform rotation time of a drum, carrying thetransparencies. Special switches for showing the picture any length oftime have to be actuated, and preselection of desired and variable timeintervals during projection is not possible.

The use of a known circuit-opening and -closing switch, which isactuated during a certain setting-time on the still-picture projectordoes not make it possible to cause the picture sequence in a preselectedtime interval relation, .and to keep the mechanism so simple as toattain the different time intervals starting from an initial position.

The aim of the invention is therefore to avoid these disadvantages andto provide a simple device with which it is possible to change thepictures in projectors by means of a timing mechanism and anintermittent switching mechanism.

This object is attained by providing a device for changing pictures in astill-picture projector having adjust- 3,270,448 Patented Sept. 6, 1966ice able time intervals, comprising a timingand intermittent switchingmechanism, each of which has a slide connected to a disc and which iscoaxially driven by means of a hollow shaft, the slide engaging at leasttwo of three contact tracks on a printed circuit, one of which is in theform of segments, wherein the quick rotating slide of the intermittentswitching mechanism is being moved after actuation of one of severalselector contacts and the timing mechanism slide which either standsstill or rotates slowly is taken over, from the initial position, bymeans of an overrunning clutch and carried back to the initial position,whereby according to the invention the timing mechanism and intermittentswitching mechanism could be driven by the same motor, having a slidingrotor, which drives by means of several gears in one position, i.e. at alow energizing current the slide of the timing mechanism and in anotherposition, i.e. high energizing current the slide of the intermittentswitching mechanism.

This arrangement is cheap to manufacture and easy to adjust, whilehaving great accuracy. Since the timing mechanism slide, as well as theintermittent switching mechanism slide start at their initial positionsduring the change of pictures, no errors are added up by stepwiseoperation. It is therefore sufiicient, for very precise operation, toarrange the switching segments at certain distances from one another,i.e. in form of conducting tracks on a printed circuit.

The driving motor could be a synchronous motor for practical purposes.The time elapsing, until the timing mechanism slide, starting from itsinitial position, engages the segment connected with the activatedselector contact, is equal to the time interval during which thesubsequent transportation [of the pictures is performed.

When the timing mechanism slide engages this selector contact, the rotorwill be transported to the other engaging position, whereby theintermittent switching mechanism slide will be moved. The latter isfaster than the timing mechanism slide and carries it along, until theintermittent switching mechanism slide reaches its initial position. Atthis point the timing mechanism slide is able to overtake the slide ofthe intermittent switching mechanism, until it reaches its initialposition. The cycle can then start again.

The arrangement and general application of the drive motor are describedin my Patent 3,041,480 (filed March 22, 1960, Ser. No. 16,789) and3,164,729 (filed March 16-, 1960, Ser. No. 15,389).

The selector contacts enable the projectionist to set the time duringwhich each individual picture is screened, by operating one or the otherof the selector keys. The various selector keys correspond to varioustime intervals in the picture changing. It is desirable to provide theselector contacts in form of pushbutton keys, having an operatingposition, and upon further depression a rest position.

When the operating position is used, the picture changes are performedduring the time associated with the particular selector key. When therest position is used, a multiple of the time associated with this keyis obtained.

In order to permit fully automatic screening, one possibility for theselector key consists in scanning a punched card, rotated by theintermittent switching mechanism. The card has recesses made by hand, inaccordance with the desired programme and allocates therefore apredetermined time interval for screening of each picture. The operatingsequence is then fully automatic. The pictures can be shown inconjunction with, for example, a tape recorder so that the pictures maybe explained.

V Construction is further simplified, if the drive mot-or carries theventilator wings as well as the projection lamp, thereby simultaneouslycooling the projecting lamp, setting the time interval and effecting theintermittent switching.

If a printed circuit is used, the whole apparatus can be small and cheapto manufacture and the resulting accuracy and variety of possiblecombinations are such as are otherwise found only in much more expensiveapparatus.

In order to permit alteration of the programme sequence, it is imporantfor the motor driving the switching mechanism to drive the latter bymeans of a slip clutch, so that the shaft of the intermittent switchingmechanism can be turned manually.

For fully automatic projection a recording tape containing theaccompanying text with metal foils constituting the selector contacts oractuating same may be used so that the change of pictures necessarilycoincides wit-h the sequence of the accompanying text instead of thepunched card.

An example of the invention is illustrated in the drawing wherein:

FIGURE 1 shows the electric circuit of an apparatus according to theinvention.

FIGURE 2 shows a portion of the operating mechanism.

FIGURE 3 shows a schematic view on a reduced scale of the over-ridingclutch shown in FIGURE 2.

According to FIGURES 1 and 2 the timingand intermittent switchingmechanism comprise three tracks on a printed circuit. The first of thesetracks is closed, the second is interrupted and the third is made up ofswitch segments. The spacings of these switch segments correspond to theselected time intervals between picture changes. An router slide ismoved by the timing mechanism and establishes the electric connectionbetween the third and second contact tracks. An inner slide is moved bythe intermittent switching mechanism and establishes the electricconnection between the first and second contact tracks. An overridingclutch between the two slides enables the slide that is moved moreslowly by the timing mechanism to be carried along by the faster slide,which is moved by the intermittent switching mechanism. It is carriedalong, until the slide moved by the switching mechanism, reaches .aninterruption in the second contact track and remains stationary, untilit is carried along next, while the slide moved by the timing mechanismruns on continuously.

FIGURE 1 shows the first contact track 1, having a connecting lug 2. Thesecond contact track 3 has an interruption 4 in the form of adepression, as to avoid burning at the beginning and the end of thistrack. The first and second tracks 1 and 3 are bridged by a slide 5mounted on a disc 6 (FIGURE 2). Any type of rotating arm can be usedinstead of a disc. The disc 6 is rigidly connected with the spindle 7.

The third contact track 8 is made up of the segments 29, 9, 10, 11,which are connected in that sequence to the second contact track 3 by aslide 112. The slide 12 is mounted on a disc 13 which is driven by thegearwheel 14 through a hollow shaft 47 surrounding the spindle 7. Themain terminals 15, 16, and the drive motor 30 are also shown, as Well asthe selector cont-acts 32, 33, 34, 35 which may be actuated manually orby the intermittent switching mechanism.

The drive motor 30 receives according to the illustrated example, afteractuation of switch 50 current through resistor 21. With a low excitingcurrent, the rotor 17 remains in the lower position, so that the gear 31meshes with gear 14 to drive the timing mechanism by the slide 12.

When the drive motor 30 receives the full amount of current across themain terminals 16 and 19, the stator will be highly excited and therotor 17 will be drawn dicated schematically.

into the stator field, assisted by the spring 51. The gear 36 thenmeshes with gear 39, causing actuation of the picture changingmechanism, and also with gear 38, which is rigidly connected to thespindle 7 and Will rapidly move slide 5.

The actual picture changing mechanism is only in- It comprises a gearwheel 39, crank and thrust rods 40, 41.

These are reciprocated in the direction of the arrow 42 depending uponthe ratio of the gearing 39. They are provided with supports 43, 44 onwhich the pictures or transparencies 45 rest. Each picture drops in aknown manner vertically to the plane of the drawing when the thrust rods40, 41 with their supports are moved appropriately, and the next picture45 may follow from above. This apparatus may be constructed in any otherusual way.

The presence of the slip coupling 36.permits the spindle 7 to be turnedby hand, by using the diagrammatically illustrated handwheel 46.According to the drawing the drive motor 30 also drives the fan above itfor the projecting lamp (not shown).

It is to be mentioned that actuation of the selector contacts 32-35 isalso possible by the gearing 39, if the sildes are to be fullyautomatic. The possibility of shaping the selector contacts 32-35 asscanning contacts of a magnetic tape onto which the contact-making foilsare stuck, is not illustrated.

It is important for the continuously rotating drive motor 30, afteractuation of switch 50 to use as little current as possible in itsnormal position, ie while driving the timing mechanism, with minimalloss of heat. High output is only required during the short time whiledriving the intermittent switching and picture changing mechanisms. Aslip clutch 36 assists the fast, andsmooth meshing of gear 36 with gears38- and 39, whereby full output of the drive motor will be permittedwithout danger of great wear.

The described apparatus functions as follows:

In the position shown, the slide 5 connects the first contact track 1 tothe second contact track 3. The drive motor 30 thereby receives afteractuating switch 50, full current, namely from the main terminal 15through connecting strip 19, the second contact track 3, the slide 5,the first contacting track 1, the connecting lug 2, as well as theconnecting strip 18 on one hand and through the main terminal 16 on theother hand. The drive motor 30 simultaneously drives the slide 6 as wellas the picture changing mechanism. The slide 5, respectively the disc 6move thereby in the direction of arrow 28 and overtake disc 13, whilerecess 48 on the disc 6 carries along with it the lever 26 on the disc13 and thus also the slide 12. The functioning of this overrunningclutch is to be seen in FIGURE 3. It is a slip clutch, because if disc13 moves in the direction of the arrow 28 relative to disc 6, then therounded-off edge 49 of disc 6 prevents it from being carried along bydisc 13.

When the slide 5 reaches the position 25, shown in dotted lines, thenthe drive motor 30 is almost de-energized, since the slide 12 has alsobroken the bridging of resistance 21. The rotor 17 again drives thetiming mechanism and the spindle 7 stops rotating. The thrust rodsactuated by the intermittent switching mechanism also stop in acorresponding position. In this position the picture is supported in theprojector and screened until the slide 12 connects the next actuatedselector contact across the corresponding contact segment through themain terminal 15. In relation to the time interval between picturechanging, the position 27 shown in dotted lines is designated as thestarting position of slide 12. This position is only temporary as can beseen from the preceding.

Depending on which of'the selector contacts 32 to 35 is closed, theterminal 15 is connected to the corresponding segment 9, 10, 11, 29 ofthe third contact track 8. The time taken by the slide 12, to pass fromthe dotted-line position 27 to the appropriate live contact segmentdesignates the time interval bettween picture changes. In FIGURE 1 theselector contact 33 is closed, for example by hand. When the slide 12reaches the position shown in full lines (FIG. 1), the drive motor 30receives full current from the main terminal 15 through the secondcontact track 3, the slide 12, the contact segment 10, the contact 33and the connecting strips 18 and 20 on one hand, as well as the mainterminal 16 on the other hand. Thus the rotor 17 meshes with the gears38 and 39. Now the picture changing mechanism is actuated andsimultaneously the slide 5 which is mechanically connected to disc 6,will be moved in the direction of the arrow 2-8. The dotted-lineposition of the slide 5 in FIG. 1 indicates this position. As soon asslide 5 reaches contact track 3, shown in full lines, after leaving gap4, the fast moving slide 5 carries inert slide 12 with it. The slide 5is left in the gap 4, as it has switched itself ofl. after leavingcontact track 3. The rotor 17 again drives the timing mechanism. Theslide 12 now overtakes slide 5 and the entire process repeats itself.

If none of the selector contacts 3235 are closed, slide 12 rotatescontinuously, without the rotor 17 being changed to drive theintermittent switching mechanism.

The time taken by the slide 12 to reach one of the energised segments ofthe contact track 8, from the dottedline position 27 represents the timeintervals at which the pictures are changed. The selector contact 32 forinstance, gives a longer time interval for changing pictures than theselector contact 34.

Instead of the four segments 9-11 and :29 shown, any desired number ofadditional segments and associated selector contacts may be provided.The drive reductions from drive motor 30 to spindle 7 and gear 14respectively, may be chosen at will. The overriding clutch may also bedifferently constructed.

The possibility to provide the stator of the drive motor with two ormore windings or a tap winding resulting in different drive positions ofthe rotor, by means of different magnetisation is also of importance. Inthis case the priming resistance 21 and thus any direct connectionbetween connecting strips 19 and 20 are eliminated. 4

The connecting lug 2 is properly connected to the winding or part of thewinding respectively, which effects the strongest magnetization, whilethe contact segments are to be connected across the appropriate selectorcontacts to the less magnetizing winding or windings.

I claim:

1. Drive mechanism for a picture-changing slide projector Withadjustable time intervals comprising a timing mechanism having a slideslowly driven by gearing and carried by a rotating par-t, whilecontacting with an interrupted contact track on a printed circuit andwith another contact track comprising conductive contact-segments on thesame printed circuit, an intermittent switching mechanism having arapidly rotating driving connection to a coaxially mounted, rotatingpart carrying a slide which slides on said interrupted contact track andon a circular track, both of which are conductive, a one-way slip clutchfor mechanically connecting the rotating parts With each other duringrotation and for electrically connecting them with the segments and withswitches, a picture-changing mechanism having a crank and thrust rods,and a motor the rotor of which in one position drives through a gear therotating part of the intermittent switching mechanism and also thepicture-changing mechanism and in another position through gears therotating part of the timing mechanism.

2. The apparatus according to claim 1, wherein the motor drives thetiming mechanism at a low magnetization of its stator.-

3. The apparatus according to claim 1, wherein the rotor is connected toa gear through the slip clutch.

4. The apparatus of claim 2, wherein the rotor is connected to a gearthrough the slip clutch.

References Cited by the Examiner UNITED STATES PATENTS 2,905,239 9/1959Dietz ZOO-37 X 2,999,425 9/ 1961 Emmel 40-79 X 3,003,997 10/ 1961Jennings 20037 X 3,015,251 1/ 1962 Pollan 40-79 X 3,151,257 9/1964Anderson 20036 X 3,210,487 10/1965 Holzer 20036 JEROME SCHNALL, PrimaryExaminer.

EUGENE R. CAPOZIO, Examiner.

W. GRI'E'B, Assistant Examiner.

1. DRIVE MECHANISM FOR A PICTURE-CHANGING SLIDE PROJECTOR WITHADJUSTABLE TIME INTERVALS COMPRISING A TIMING MECHANISM HAVING A SLIDESLOWLY DRIVEN BY GEARING AND CARRIED BY A ROTATING PART, WHILECONTACTING WITH AN INTERRUPTED CONTACT TRACK ON A PRINTED CIRCUIT ANDWITH ANOTHER CONTACT TRACK COMPRISING CONDUCTIVE CONTACT-SEGMENTS ON THESAME PRINTED CIRCUIT, AN INTERMITTENT SWITCHING MECHANISM HAVING ARAPIDLY ROTATING DRIVING CONNECTION TO A COAXIALLY MOUNTED, ROTATINGPART CARRYING A SLIDE WHICH SLIDES ON SAID INTERRUPTED CONTACT TRACK ANDON A CIRCULAR TRACK, BOTH OF WHICH ARE CONDUCTIVE, A ONE-WAY SLIP CLUTCHFOR MECHANICALLY CONNECTING THE ROTATING PARTS WITH EACH OTHER DURINGROTATION AND FOR ELECTRICALLY CONNECTING THEM WITH THE SEGMENTS AND WITHSWITCHES, A PICTURE-CHANGING MECHANISM HAVING A CRANK AND THRUST RODS,AND A MOTOR THE ROTOR OF WHICH IN ONE POSITION DRIVES THROUGH A GEAR THEROTATING PART OF THE INTERMITTENT SWITCHING MECHANISM AND ALSO THEPICTURE-CHANGING MECHANISM AND IN ANOTHER POSITION THROUGH GEARS THEROTATING PART OF THE TIMING MECHANISM.